Lock assembly

ABSTRACT

A lock assembly has a stationary barrel. A cylinder having one or more sections is rotatable in the barrel and defines a shear line. Tumbler assemblies in radial bores in the cylinder and barrel are radially and circumferentially spaced. Pins may have different sizes and shapes and may terminate in flat wafer edges exposed to an axial bore in the cylinder. The cylinder receives a key shaft formed with recesses arranged to correspond with the spacing of the tumbler assemblies. Key engaging means is provided at the inner end of the bore in the cylinder to engage an appropriately shaped end of the key shaft. The key shaft may be magnetized to attract magnetic pins of some tumbler assemblies radially into the bore. Radial bores may be countersunk; pins and pin drivers may be ridged and grooved; and spring means can bear tangentially on the cylinder to stabilize it, all to forestall picking of the lock assembly.

United States Patent Hughes [54] LOCK ASSEMBLY [72] inventor: BenjaminF. Hughes, Route 1, PO. Box 120, Morris, Ala. 35116 Filed: June 3,1970Appl.No.: 42,944

[56] References Cited UNITED STATES PATENTS [151 3,656,328 1 Apr. 18,1972 2,294,495 9/ 1942 Woodruff ..70/364 A FOREIGN PATENTS ORAPPLICATIONS 690,883 5/1940 Germany ..70/358 Primary Examiner-Albert 6.Craig, Jr, Attorney-Polachek & Saulsbury [5 7] ABSTRACT A lock assemblyhas a stationary barrel. A cylinder having one or more sections isrotatable in the barrel and defines a shear line. Tumbler assemblies inradial bores in the cylinder and barrel are radially andcircumferentially spaced. Pins may have different sizes and shapes andmay terminate in flat wafer edges exposed to an axial bore in thecylinder. The cylinder receives a key shaft formed with recessesarranged to correspond with the spacing of the tumbler assemblies. Keyengaging means is provided at the inner end of the bore in the cylinderto engage an appropriately shaped end of the key shaft. The key shaftmay be magnetized to attract magnetic pins of some tumbler assembliesradially into the bore. Radial bores may be countersunk; pins and pindrivers may be ridged and grooved; and spring means can beartangentially on the cylinder to stabilize it, all to forestall pickingof the lock as- 18 Claims, Drawing Figures 1,047,483 l2/1912Augenbraun.. /364A 456,917 7/1891 Taylor.... ..70/378 1,755,847 4/1930Stevens 70/364A 2,246,112 6/1941 Speer ..70/419 3,512,382 5/1970Checketal. ..70/364A 24,709 7/1859 Bacon ..70/364A 1 1,020,208 3/1912Laughlin..... ...70/364A 2,004,432 6/1935 Fitzgerald ..70/419 ma 74 T1175) L/Tgm 3 ill? kt m 126 l e Mimi 170 7 Q 150 K 266" 11 x 1561' I 267PATENTEDAPR i8 I972 SHEET 1 BF E L r g T m @w m Q NM Y QM M NwN N @w E Twk fin E L QWN BK .Nm m.

PATENTEDAPR 18 I972 656,328

' sum 3 OF 5 INVENTOR. BENJAMIN E HUGHES F .15 BY q 3? 51- T -5a 0 Q05 5a 2 0 500e,

PATENTEDAPRWIBYE 3,656,328

SHEET u nr 5 7-1 .75.. IF-9-15. 7- 1.27. Fl fi INVENTOR. BENJAMIN FHUGHES BY W'W? I RA 5X LOCK ASSEMBLY This invention relates to apick-resistant lock and key therefor, and more particularly concerns acylinder lock having features which make it extremely difficult orimpossible to pick.

Many innovations have been proposed to render pickproof cylinder locksemploying pin tumblers. Generally they have not proven successfulbecause their design was based upon an insufficient understanding of thetechniques by which an expert picks a lock.

In picking a lock, an expert will attempt to determine which oftthetumbler pins has the tightest fit in the lack. The picker will raisethis pin tumbler first. At the same time he applies torque to the keycylinder or plug so that the cylinder rotates sufficiently to present aledge at the shear line between cylinder and barrel of the lock at theraised pin tumbler, so

.this pin rests on the ledge. This first pin is thus prevented fromreentry into the key cylinder. The lock picker then proceeds .totpickthe remaining tumbler pins in similar fashion, taking care not todisturb any raised pin.

In all the pick resistant and so-called pickproof locks proposedheretofore, no basic change is made in the arrangement of the tumblerpins themselves. All the tumbler pins have the same sizes andconstruction and all are axially movable outwardly against spring bias.This facilitates the picking of the lock. Furthermore the rotatable keycylinder is exposed and accessible at the outer face of the lock. Thisagain facilitates picking of the lock. Some locks proposed have amultiplicity of rows of pin tumblers. Such locks are typically describedin U.S. Pat. Nos. 3,167,943 and 3,303,677, but these locks suffer thedeficiencies mentioned above among others. As a result they only prolongthe time required by an expert lock picker to pick the lock.

The present invention is directed at an improved pick resistant orpickproof lock which embodies a multiplicity of features allspecifically directed at defeating picking of the lock by conventionalmethods. According to the invention, a cylinder lock is provided havinga round keyhole. The key is cylindrical and has depressions, slots,recesses or dimples formed therein. It has no axially projecting teethas is conventional in flat keys for cylinder locks. At the front end ofthe lock cylinder or plug is a flat annular ring which is separate fromthe lock cylinder; and a stationary cover plate is disposed in front ofthis protective ring. This prevents applying torque at the outside ofthe lock cylinder to pick the lock. The lock cylinder may be made in twoor more parts which rotate together but in which there may be somecircumferential and axial play. This effectively prevents turning thelock cylinder off center for picking. The innermost end part or sectionof the cylinder is arranged to be engaged by a specially shaped end ofthe key shaft. The key shaft may be magnetized for pulling magnetictumbler pins inwardly rather than outwardly. The tumbler pins whichoperate magnetically are flush with the inside of the keyhole. Attemptsto pick the lock by pushing these magnetic pins radially outward defeatspicking the lock. No conventional picking tools can pull these magnetictumbler pins inwardly and hole them stationary precisely at the shearline while other pins are picked. In the lock, some tumbler pins are notmagnetically operated, and these are located in random positions axiallyand circumferentially around the key cylinder, as are the magneticallyoperated pins. In the lock cylinder, some tumbler pins fit loosely intheir holes and stay loose and free at all times to defeat picking ofthe lock by engaging a picked pin on a ledge of the pin hole at theshear line. Pins may have different diameters to project differentdistances in the keyhole. Tapered pin drivers or plungers can beprovided which also make picking more difficult. Spring means can alsobe provided to keep the key cylinder under circumferential springtension which further protects the lock against picking. In magnetic pintumblers, pins of different diameters are pulled inwardly differentaxial distances into depression in the key. The depressions and slots inthe key shaft have different depths. Some tumbler pins have flat, waferends which are not possible to pick by conventional methods of pickingcylindrical tumbler pins. When a lock has a plurality of pickresistantfeatures such as mentioned above, distributed in a random way, it isrendered substantially pickproof.

The above and other features, objects and advantages of the inventionwill become apparent from the following detailed description takentogether with the drawings, wherein:

FIG. 1 is an enlarged longitudinal sectional view of a lock embodyingthe invention.

FIGS. 2, 3 and-4 are cross sectional views taken on lines 2- 2, 3-3 and4-4 respectively of FIG. 1.

FIG. 5 is a perspective view of an insert in the key cylinder or plugwhich engages a specially shaped end of a cylindrical key.

FIG. 6 is a side view of a key according to the invention, part beingbroken away to show a magnetized insert in the key shaft.

FIG. 7 is a cross sectional view taken on line 7-7 of FIG. 6.

FIG. 8 is an enlarged cross sectional view taken on line 8-8 of FIG. 7.

FIG. 9 is a fragmentary longitudinal sectional view similar to an endportion of the lock of FIG. 1, showing structural features of anotherlock. 7

FIG. 10 is a perspective view of an insert in the end of the lockcylinder of the lock of FIG. 9.

FIG. 11 is a side view of another key structure according to theinvention.

FIG. 12 is an enlarged cross sectional view taken on line 12-12 of FIG.11.

FIG. 13 is an exploded perspective view of parts of the key of FIG. 11.

FIG. 14 is a sectional view similar to FIG. 12, another key structure.

FIG. 15 is an enlarged cross sectional view taken on line 15-15ofFIG.11.

FIGS. 16-26 inclusive are cross sectional views similar to part of FIG.15, showing other key structures.

FIG. 27 is a fragmentary longitudinal sectional view similar to aportion of FIG. 1, showing an end portion of another lock.

FIG. 28 is a side view of a key which can be used with the lock of FIG.27.

FIG. 29 is an exploded perspective view showing the end of the key ofFIG. 28 and an insert used in the lock cylinder of FIG. 27.

FIG. 30 and FIG. 31 are cross sectional views taken on lines 30-30 and31-31 respectively of FIG. .29.

FIGS. 32, 34, 36 and 38 are cross sections similar to FIG.30 of othercylinder inserts.

FIGS. 33, 35, 37 and 39 are cross sections similar to FIG.31 of otherkeys used with the cylinder inserts of FIGS. 32, 34, 36 and 38respectively.

FIG. 40 is a longitudinal sectional view of another lock.

FIG. 41 is a cross sectional view taken on line 41-41 of FIG. 40.

FIG. 42 is a cross sectional view taken on line 42-42 of FIG. 40,through the rotatable cylinder of the lock.

FIGS. 43, 44, 45 and 46 are exploded perspective views of pin tumblerassemblies employed in the lock of FIG. 40.

FIG. 47 is a side view of a key usable with the lock of FIG. 40.

FIGS. 48 and 49 are cross sectional views and FIG. 50 is an end view onan enlarged scale taken on lines 48-48, 49-49 and 50-50 of FIG. 47.

Referring first to FIGS. 1-4, there is shown a lock assembly comprisingan outer cylindrical cup shaped casing 102 having a circular front endface plate 104 secured by screws 106 to annular flange 108 of thecasing. The circular rear end 110 of the casing has an opening 112through which extends an eccentrically disposed bolt or cam 114. Insidethe casing is a stationary cylindrical barrel 116. A cylindrical plug orlock cylinder assembly 118 having a main front section 117 and a rearend section 119 is rotatably disposed in bore 120 in the barrel. Thejunction of the outer side of the lock cylinder and showing bore 120defines a shear line L. Bolt 114 is secured to end section 119 of thecylinder 118.

The front end of the main cylinder section 117 is formed with an annularflange 122 which rotatably abuts a shoulder 124 in the barrel. A flatring 126 is disposed between the front end of the cylinder and faceplate 104. This ring is separate from the cylinder and may beindependently rotatable or may be fixed with respect to the face plate.Key holes 128, 129 in the face plate and ring are axially aligned andregister with axial bore 130 in cylinder section 117. This bore iscylindrical. Engaged with cylinder section 117 is a plug 132 fitted intoa blind hole 136 in section 117 and axially movable in hole 138 incylinder section 119. A coil spring 140 in hole 138 urges the plug 132into hole 136. By this arrangement the cylinder section 117 and endsection 119 are slightly movable axially and circumferentially withrespect to each other while remaining in axial alignment in bore 120 ofthe barrel 116. This relative movement of the two cylinder parts orsections will forestall any attempt at lock picking since any torqueapplied to the main cylinder section 117 will not be followed preciselyby end section 119.

A cup shaped cylindrical insert 142 is frictionally fitted in bore 144in cylinder section 119; see FIGS. 1, 2, 4 and 5. The insert is held inplace by a lateral key 146. Insert 142 has an axial bore 150 which mayhave any shape regular or irregular. Bore 150 can receive a suitableshaped end of a key for turning the cylinder assembly 118 as will bedescribed below in connection with FIGS. 6-8. A plurality of radialbores 154 is formed in barrel 116. These bores are axially aligned withbores 156 in cylinders sections 117 and 119. Assemblies of tumbler pins,pin drivers and springs are disposed in the several bores. The bores arespaced apart axially and circumferentially of the barrel 116 andcylinder 118 in various random ways. Some of the different tumblerarrangements which can be used are shown in FIGS. 1, 2 and 3. Beforedescribing these tumbler assemblies, it will be well to refer first toFIGS. 6 to 8 where key 200 is shown.

The key 200 has a cylindrical shank or shaft 202 at least as long as thebore 130 in cylinder section 117. At the front end of the key is ahandle 203 of any convenient shape which can be manually grasped forinserting the key shaft in keyholes 128, 129 and bore 130, and forturning the key. A flattened upper edge 204 can be provided to indicatethe proper key position for inserting it in the lock. ln key shaft 202is a multiplicity of recesses, dimples, grooves, and depressions 210spaced apart axially and circumferentially in random locations allcorresponding to similarly located radial bores in the sections 117 and119 of lock cylinder 118. At the end of the key shaft is a stud 212having a shape in cross section which corresponds with and fits intobore 150 in cylinder insert 142 for turning the cylinder assembly 118.In some recesses such as recesses 210a and 210b, are fitted strongpermanent magnets 214 and 215 which operate magnetic tumbler assembliesin the lock by magnetically drawing their tumbler pins radially inwardof the lock into the recesses. Other recesses in the key shaft havedifferent depths and diameters for axially lifting tumbler pinsdifferent distances to align pin drivers with the shear line. Some ofthe different tumbler arrangements which can be used and operated by key200 will not be explained by referring again to FIGS. 1, 2 and 3.

Tumbler assembly T1 has a freely rotatable ball 160 seated at aconstricted end of bore 156a and extending partially into bore 130. Acylindrical pin 162 bears on the ball. A cylindrical pin driver 164bears on pin 162 just below or inside of the shear line L. Coil spring166 bears on the cylindrical driver. This tumbler arrangement is verydifficult to pick since the rotatable ball allows no stable surface fora picking tool to engage. Furthermore adjacent edges of bores 154a and156a are countersunk so there is no ledge at the shear line for driver164 to engage. In addition adjacent ends of the pin and driver havegrooves and ridges 165 any one of which can conceivably be engaged atthe shear line L, which would give an expert lock picker a falseindication of where the shear line is, since the inner end of the driver164 would not be located precisely at the shear line. In operation, theball, pin and driver will be retracted when key shaft 202 is insertedinto bore 130. Then the ball will rest in a registering recess in thekey shaft. This aligns the tip of driver I 74 with shear line L innerend of driver 164 with shear line L. If all other pin drivers in thelock are aligned with shear line L then the cylinder 1 18 can be turnedto turn bolt 1 14.

Tumbler assembly T2 has a pin 170 made of magnetic material. The innerfree end of the pin is flush with the constricted end of bore 156b. Acoil spring 172 around the pin tends to retract the pin. Pin driver 174is also magnetic and is integral with pin 170. This pin driver has a tipof narrow diameter bearing against a cylindrical magnet 174. This magnetis weaker than an operating magnet employed in the key described below.Magnet 174 abuts a cylindrical stop 175 in bore 154b. When the key isproperly inserted into the lock, magnet 214 in the key shaft shown inFIG. 7 will align with pin 170 and will draw this pin magnetically intorecess 210a. This will align the tip 173 of driver 174 with the shearline L in proper position for turning the cylinder assembly 118. It willbe noted that the pin 170 is pulled axially inward to operate thistumbler assembly. When the key is released spring 172 retracts the pinand driver, and tip 173 of the driver assumes a position across theshear line. Magnet 174 cooperates with spring 172 in keeping the freeend of pin 170 flush with the surface of bore 130. It will move withdriver 174 up to the shear line L and will separate therefrom when thecylinder assembly 118 is turned.

Tumbler assembly T3 has a pin projecting slightly from bore 156c whichis narrower than bores 156a and 156b. The pin has a head 182 bearing ona shoulder in bore 156c. Driver 184 has a tip 186 bearing on head 182and extending out of bore 154c and across the shear line L. Spring 166cbears on driver 184. In operation the pin will initially be retracted askey shaft 202 is moved axially in bore 130. Finally the pin will engagein a recess 210 in the key shaft. The pin will be slightly retracted tolocate the tip of the driver at the shear line to permit the cylinderassembly to turn with the key.

Tumbler assembly T4 has a pin 188 which is diametrally wider than pin180. Pins 180 and 188 each have an end portion extending into the bore130, these end portions being substantially hemispherical and because ofthe difference in diameter thereof they extend axially a differentdistance into bore 130. The head 189 of the pin rests on the shoulder inbore 156d. Cylindrical driver 190 bears on head 189 and extends acrossthe shear line. Spring 166d bears on pin driver 190. This assembly actslike assembly T3 where the end of the pin rests in a recess in the keyshaft to align the faces of the cylindrical pin head and pin driver withthe shear line L.

Tumbler assembly T5 has a cylindrical pin 192 formed with a conical tip194 extending partially out of constricted inner end of bore 156e. Theupper end of the pin is formed with ridges and grooves as in pin 162 oftumbler assembly Tl. Cylindrical driver 194 has ridges and grooves as inpin driver 164. Edges of bores 154a and 156e are countersunk. Asexplained previously this arrangement makes picking very difficult. Alsothe conical end of the pin makes it difficult to engate a pick thereon.Spring 166e bears on the pin driver. The conical pin and extendsslightly more into bore 130 than pins having ends of larger diameter.The recess into which this pin end will engage will be similarly shapedin the key shaft. The mating faces of the pin driver and pin will belocated at the shear line when the key shaft is properly inserted in thelock.

Tumbler assembly T6 has a conical pin 196 which fits snugly into theconical bore 156f. This contrasts with the other radial tumbler pinsdescribed which fit loosely in the bores of the cylinder assembly. Thelower end of pin driver 198 in bore l54f is also conically tapered.Spring 166f bears on the pin driver. The conical arrangement makes itdifficult to pick or impossible to engage and hold this pin driver onthe edge of bore 156f which is countersunk. Also the conical pin isdifficult to engage with a picking tool. When the key is inserted themating faces of pin and driver are located at the shear line L.

Tumbler assembly T7 is magnetically operated. Cylindrical pin 250 fitsloosely in bore 156g. Its inner end is flush with the surface of bore130. Pin 250 is made of magnetic material such as stainless steel. Astationary magnet 252 holds the pin in place. Pin 250 crosses the shearline L. When a magnet such as magnet 215 in the key shaft, shown in FIG.6 is aligned with pin 250, the pin will be pulled radially inward intothe bore 130 to align the outer end of the pin with the shear line L.When the key is removed, magnet 252 retracts the pin again. Magnet 215will be stronger than magnet 252 to advance the pin against the pull ofmagnet 252.

Tumbler assembly T8 has a pin 254 formed with a wafer tip 256. Pin 254is located in radial bore 156 in cylinder section 119. Tip 256 extendsthrough slot 258 in cylindrical insert 142. This wafer tip will engageon recess 260 formed in stud 212 shown in FIG. 6. Driver 262 bears onpin 254 and spring 166h bears on the pin driver. The pin driver extendsacross shear line L and aligns with the shear line when tip 256 isengaged in key recess 260.

Tumbler assembly T9 has a cylindrical pin 264 loosely fitted in bore156j. The outer end of the pin is hemispherically shaped with a fiatouter face. Pin driver 266 is also hemispherically shaped at the endwhich bears on pin 264. Spring 166j bears on the pin driver. Thisarrangement is very difficult to pick. The pin rocks laterally on thecurved shoulder 267 in the cylinder section 117 at the outer end of bore156j. Pin 265 projects slightly into bore 130 and will be retracted bythe key shaft. When the free end of the pin rests in a recess in the keyshaft, the flat juxtaposed faces of the pin and pin driver will bealigned with the shear line L.

Tumbler assembly T10 is magnetically operated. Pin 270 is magnetic andits free end is flush with the inside of bore 130. The pin 270 anddriver 272 are balanced between springs 274 and 166k. The pin will beadvanced radially inwardly into bore 130 by a magnet in the key shaft.This will align the juxtaposed ends of the pin and pin driver at theshear line. Tumbler assemblies T11, T12 and T14 are respectively similarto tumbler assemblies T7, T3 and T4 so no further explanation isrequired.

Tumbler assembly T13 is magnetically operated. Pin 280 has a head 282crossing shear line L and engaged by fixed magnet 284. The pin isadvanced axially inward by a magnet in the key shaft 202 against thetension is spring 286. The magnet 284 cooperates with spring 286 inholding the pin in place with its inner end flush with the inside ofbore 130.

FIGS. 1 and 4 show a further arrangement for making it more difficult topick this lock. Kick springs 293 are set in oblique bores 294 in thebarrel. The springs are axially compressed and bear against plugs 295 atouter ends. The springs bear laterally against the cylinder section 117,and resist turning of the cylinder assembly 118. Any slight turning ofthe cylinder assembly in a picking attempt will be countered by thesprings 293 which will tend to return the cylinder assembly to itsstable locked position.

In FIG. 9 is shown part of another lock 100A which is generally similarto lock 100 of FIGS. l-4 and corresponding parts are identicallynumbered. In lock 100A end section 1190 of the cylinder assembly issecured to main cylinder section 117a by screws 298. Cylindrical insert142a also shown in FIG. 10 has a hexagonal bore 150a to receive acorresponding shaped end of a key such as key 200A of FIG. 11. Theinsert extends partially into the end of cylinder section 119a. Thus thetorque exerted by the key is applied to both sections simultaneously.

Key 200A shown in FIGS. 11, 12, 13 and 15 is formed in several parts.The key has a tubular shaft or shank 202a in which is axially securedmagnetized bar or bar magnet 300. The bar magnet is hexagonal in crosssection with recesses 302 aligned with holes 303 in shaft 202a. Themagnet will draw ends of magnetic pins such as pin 250 into bore 130 forclearing the shear line L. Recess 268a in the exposed end 300a of bar300 engages wafer tip 256 of pin 254. Shaft 2020 has an integral handle203a.

FIG. 14 shows a section of another key 2008 which is similar to key 200Aexcept that the inserted bar 300 is not magnetized. Instead cylindricalmagnets 304 are inserted in recesses 306 in the bar for attracting themagnetic pins of magnetically operated tumbler assemblies such asdescribed above.

FIGS. 16 through 26 show other keys 200B-200L each of which has adifferently shaped key end .300b-300m. Some key ends such as key ends3001: and 3000 can have regular geometrical shapes such as triangular orsquare with ridges 308, 310 along the sides. The key ends can have otherregular pologonal shapes. Key ends 300d, 3002 and 300f are respectivelypentagonal, parallelogrammic, and octagonal. Still other shapes arepossible. Key ends 300g and 300h are parts of circles. Key ends 3001',and 300k are crosses. Key end 300j is circular with V-shaped notches 312at opposite sides. Key end 300m is circular with a groove 314 at oneside. Other geometrical shapes can be provided. The cylindrical insertsin the end sections of the lock cylinders will have correspondinglyshaped bores.

FIG. 27 shows part of a lock B which is generally similar to lock 100and corresponding parts are identically numbered. This lock has acylindrical insert 142b provided with a transversely extending wire orpin 320. As shown in FIG. 29 this insert receives end 333 of cylindricalkey shaft 202k. A diametral slot 355 is formed in the cylindrical end ofthe shaft. The bore 15% in the insert is cylindrical. It is of coursepossible to provide polygonal shaped key ends such as shown in FIGS. 8and 15-20, and to form slots therein for engaging transverse pinsinserted in the corresponding lock inserts. In any case the slotted end333 of key 200N shown in FIGS. 28, 29 and 31 will engage with thetransverse pin or wire 320 of insert l42b shown in FIGS. 27, 29 and 30.Thus when the tumbler assemblies are all properly aligned with the shearline L of the lock, turning of key 200N will rotate the cylinderassembly 118. Notch or recess 268 in the key end. receives and engageswafer end 256 of pin 254.

FIGS. 32, 34, 36 and 38 show other lock inserts 142c-142f. These havetwo pins 340-343 which may be parallel, crossed or angular to eachother. Keys with correspondingly slotted ends are shown in FIGS. 33, 35,37 and .39. Key end 333a has two parallel slots 335a. Key ends 3331) and3330 have crossed slots 335b, 3356 and key end 333d has angularlydisposed slots 333d. Other arrangements of pins and slots can beprovided.

Lock 100C shown in FIGS. 41 and 41 is generally similar to the lockpreviously described and corresponding parts are identically numbered.In lock 100C, a plurality of tumbler assemblies are provided near thefront end of the lock. Each of these assemblies has a ball 350protruding into axial bore C; see FIGS. 40 and 42. The main cylindersection 1176 is formed with a plurality of radial bores 352 alignedaxially with radial bores 354 in barrel 1160. These balls serve asobstructions to entry of picks into the bore 1300 of the lock. FIG. 43shows parts of tumbler assembly T15 which includes a pin 356 and driver358 having conical abutted ends 359 of reduced diameter. Parts oftumbler assembly T16 shown in FIG. 44 include cylindrical pin 360 anddriver 370 Ridges and grooves are formed in adjacent ends. Edges ofbores 352 and 354 at the shear line L' are countersunk. Springs 372 urgethe pins, drivers and balls radially inward of the lock cylinder. Thisarrangement is very difficult to pick successfully.

Other tumbler assemblies T17 have pins 375 formed with flat wafer tips376; see FIG. 46. The main cylinder section 117c is formed withlongitudinally extending radial slots 380 in which these flat wafer tipsor ends are slidably fitted. Ends of the tips extend into bore 1300.Pins 375 slide in radial bores 382 in cylinder section 117c. Pin drivers384 slide in bores 386 in the barrel. Springs 388 urge the pins and pindrivers radially inwardly.

All these flat wafer tips or ends 376 will be engaged in slots 390formed in cylindrical shaft 2026 of key 400 shown in FIGS. 47-50 towhich reference is now made.

The key shaft 202c has a circumferential groove 402 to receive andengage balls 350 so that pin drivers 358 and 370 are retracted to theshear line L. Handle 406 is disposed adjacent to groove 402. At the freepointed end 404 of the shaft are crossed slots 406 similar to thearrangement of FIG. 37 for engaging crossed wires or pins 408 extendingdiametrally through cylinder end section 119a clearly shown in FIG. 40.Insert magnets 412 are inserted in holes 414 in the key shaft. Thesemagnets attract magnetic pins such as pin 418 of tumbler assembly T18shown in FIG. 41. There the head 419 of the pin is normally held by coilspring 420 and magnet 422 in aligned bores 424, 426, with head 419extending across the shear line L.

It will be noted that the cross wires 408 bear the strain of turning thecylinder assembly 1180 and bolt 114. To relieve this strain somewhat, anauxiliary tumbler assembly T20 shown in FIGS. 40, 41 and 45 is provided.Pin 430 is axially movable in a radial bore 432 formed in cylindersection 1170. The pin has a wafer tip 434 extending through a slot 380into bore 1300 for engagement in a slot 390 in the key shaft. Spring 436bears on the pin and against an abutment disc 438 which slides aroundthe inside of barrel 1166 when the cylinder assembly 118c is turned. Bythis arrangement, the engagement of pin 430 with the key shaft 202aserves to turn the cylinder assembly with the turning key shaft. It willbe noted that the wafer tip 434 projects into bore 1300 much furtherthan the other wafer tips 376, and serves a primary function of engagingthe key to turn the shaft assembly, while the wafer tips 376 primarilyserve to align the pins and pin drivers with the shear line L.

All the locks and lock features described serve in one way or another tomake picking of the lock more difficult. When a lock has a plurality ofanti-picking features embodied therein, picking becomes so difficultthat for all practical purposes, the lock is rendered pickproof. Not allthe features described, obviously, can be incorporated in every lock. Ajudicious selection is required, depending on security requirements,cost, size, and similar considerations.

While a limited number of embodiments of the invention has beendescribed it will be understood that this has only been by way ofillustration, since other modifications will readily occur to thoseskilled in the art.

What is claimed is:

1. A lock assembly, comprising a barrel having a first bore therein; acylinder rotatably disposed in said bore to define a shear linetherewith, said cylinder having an axial second bore for receiving theshaft of a key inserted through one end of said second bore; keyengaging means at the other end of said second bore; a plurality ofspaced apart tumbler pin assemblies, said cylinder and said barrelhaving aligned radial bores respectively containing said tumblerassemblies, each of said tumbler assemblies comprising a pin engageablein a recess in said key shaft with a part of the tumbler assemblynormally disposed across the shear line, each tumbler assembly beingarranged so that said part of the tumbler assembly clears the shear linewhen the pin is engaged in said recess to permit turning of the cylinderby the key, said cylinder comprising two axially aligned cylindricalsections; spring biased means loosely connecting the two cylindricalsections and arranged to permit slight relative radial and axial andcircumferential movement against axially directed spring bias betweenthe two sections; said barrel having other bores therein extendingtangentially of one of the cylindrical sections at opposite sidesthereof; and coiled kick springs in said other bores bearing laterallyagainst said one cylindrical section, and opposing slightcircumferential movements of said one cylindrical section in said firstbore to forestall picking of the tumbler assemblies.

2. A lock assembly as defined in claim 1, wherein said radial bores andtumbler assemblies are spaced apart circumferentially and axially ofsaid cylinder.

3. A lock assembly as defined in claim 2, wherein at least one of thetumbler assemblies has a pin extending into said second bore for liftingby said key shaft a predetermine radial distance when the key isinserted into the second bore.

4. A lock assembly as defined in claim 2, wherein at least one other ofsaid tumbler assemblies has another pin with a free inner end disposedflush with the inside of said second bore, said other pin being made ofmagnetic material for magnetic attraction by said key shaft to move saidother pin radially into said second bore, so that a part of said othertumbler assembly clears said shear line.

5. A lock assembly as defined in claim 1, wherein at least one of saidtumbler assemblies has a tapered pin fitting snugly in a tapered radialbore in said cylinder.

6. A lock assembly as defined in claim 1, wherein at least one of saidtumbler assemblies has a pin formed with a flat wafer edge to engage ina slot in the key shaft.

7. A lock assembly as defined in claim 1, wherein the pins of sometumbler assemblies have different diameters and project differentdistances into said axial second bore.

8. A lock assembly as defined in claim 1, further comprising at leastone annular plate member disposed at and covering one end of saidcylinder and independently rotatable to prevent engagement of said oneend of the cylinder and thus prevent picking of the lock.

9. A lock assembly as defined in claim 1, further comprising a keyhaving a cylindrical key shaft formed with a plurality of recessescircumferentially and axially spaced around the shaft to correspond withthe spacing of said tumbler assemblies for receiving respective pinsthereof.

10. A lock assembly as defined in claim 9, wherein said shaft has a freeend shaped to engage with said key engaging means at the other end ofsaid second bore, said free end of the shaft having a tapered tip tofacilitate entry of the shaft into said second bore to lift pinsprojecting therein.

11. A lock assembly as defined in claim 10, wherein both said free endof the key shaft and said key engaging means are noncircular in crosssection.

12. A lock assembly as defined in claim 10, wherein said free end of thekey shaft has at least one slot therein, and wherein said key engagingmeans comprises at least one cross pin engageable in said slot in thekey shaft.

13. A lock assembly as defined in claim 9, wherein said key shaft ismagnetized at least in part, and wherein at least one other of saidtumbler assemblies has another pin with a free inner end disposed flushwith the inside of said second bore, said other pin being made ofmagnetic material for magnetic attraction by said key shaft to move saidother pin radially into said second bore, so that a part of said othertumbler assembly clears said shear line.

14. A lock assembly as defined in claim 1, wherein at least some of saidradial bores have countersunk ends at said shear line to forestallpicking of the tumbler assemblies thereat.

15. A lock assembly as defined in claim 1, wherein at least some of thetumbler assemblies each comprises a pin driver juxtaposed to an innerend of pin; and a coil spring bearing on the pin driver.

16. A lock assembly as defined in claim 4, wherein said other tumblerassembly includes a coil spring arranged to retract said other pin whenthe key shaft is removed from said other bore.

17. A lock assembly as defined in claim 16, wherein said other tumblerassembly comprises a magnet for cooperating with said spring in holdingsaid other pin with inner end flush with said second bore.

18. A lock assembly as defined in claim 14, wherein at least one of thetumbler assemblies includes a pin driver, both said pin and pin driverhaving ridged and grooved abutted edge portions near the shear line toforestall picking of the tumbler assembly.

1. A lock assembly, comprising a barrel having a first bore therein; acylinder rotatably disposed in said bore to define a shear linetherewith, said cylinder having an axial second bore for receiving theshaft of a key inserted through one end of said second bore; keyengaging means at the other end of said second bore; a plurality ofspaced apart tumbler pin assemblies, said cylinder and said barrelhaving aligned radial bores respectively containing said tumblerassemblies, each of said tumbler assemblies comprising a pin engageablein a recess in said key shaft with a part of the tumbler assemblynormally disposed across the shear line, each tumbler assembly beingarranged so that said part of the tumbler assembly clears the shear linewhen the pin is engaged in said recess to permit turning of the cylinderby the key, said cylinder comprising two axially aligned cylindricalsections; spring biased means loosely connecting the two cylindricalsections and arranged to permit slight relative radial and axial andcircumferential movement against axially directed spring bias betweenthe two sections; said barrel having other bores therein extendingtangentially of one of the cylindrical sections at opposite sidesthereof; and coiled kick springs in said other bores bearing laterallyagainst said one cylindrical section, and opposing slightcircumferential movements of said one cylindrical section in said firstbore to forestall picking of the tumbler assemblies.
 2. A lock assemblyas defined in claim 1, wherein said radial bores and tumbler assembliesare spaced apart circumferentially and axially of said cylinder.
 3. Alock assembly as defined in claim 2, wherein at least one of the tumblerassemblies has a pin extendiNg into said second bore for lifting by saidkey shaft a predetermined radial distance when the key is inserted intothe second bore.
 4. A lock assembly as defined in claim 2, wherein atleast one other of said tumbler assemblies has another pin with a freeinner end disposed flush with the inside of said second bore, said otherpin being made of magnetic material for magnetic attraction by said keyshaft to move said other pin radially into said second bore, so that apart of said other tumbler assembly clears said shear line.
 5. A lockassembly as defined in claim 1, wherein at least one of said tumblerassemblies has a tapered pin fitting snugly in a tapered radial bore insaid cylinder.
 6. A lock assembly as defined in claim 1, wherein atleast one of said tumbler assemblies has a pin formed with a flat waferedge to engage in a slot in the key shaft.
 7. A lock assembly as definedin claim 1, wherein the pins of some tumbler assemblies have differentdiameters and project different distances into said axial second bore.8. A lock assembly as defined in claim 1, further comprising at leastone annular plate member disposed at and covering one end of saidcylinder and independently rotatable to prevent engagement of said oneend of the cylinder and thus prevent picking of the lock.
 9. A lockassembly as defined in claim 1, further comprising a key having acylindrical key shaft formed with a plurality of recessescircumferentially and axially spaced around the shaft to correspond withthe spacing of said tumbler assemblies for receiving respective pinsthereof.
 10. A lock assembly as defined in claim 9, wherein said shafthas a free end shaped to engage with said key engaging means at theother end of said second bore, said free end of the shaft having atapered tip to facilitate entry of the shaft into said second bore tolift pins projecting therein.
 11. A lock assembly as defined in claim10, wherein both said free end of the key shaft and said key engagingmeans are noncircular in cross section.
 12. A lock assembly as definedin claim 10, wherein said free end of the key shaft has at least oneslot therein, and wherein said key engaging means comprises at least onecross pin engageable in said slot in the key shaft.
 13. A lock assemblyas defined in claim 9, wherein said key shaft is magnetized at least inpart, and wherein at least one other of said tumbler assemblies hasanother pin with a free inner end disposed flush with the inside of saidsecond bore, said other pin being made of magnetic material for magneticattraction by said key shaft to move said other pin radially into saidsecond bore, so that a part of said other tumbler assembly clears saidshear line.
 14. A lock assembly as defined in claim 1, wherein at leastsome of said radial bores have countersunk ends at said shear line toforestall picking of the tumbler assemblies thereat.
 15. A lock assemblyas defined in claim 1, wherein at least some of the tumbler assemblieseach comprises a pin driver juxtaposed to an inner end of pin; and acoil spring bearing on the pin driver.
 16. A lock assembly as defined inclaim 4, wherein said other tumbler assembly includes a coil springarranged to retract said other pin when the key shaft is removed fromsaid other bore.
 17. A lock assembly as defined in claim 16, whereinsaid other tumbler assembly comprises a magnet for cooperating with saidspring in holding said other pin with inner end flush with said secondbore.
 18. A lock assembly as defined in claim 14, wherein at least oneof the tumbler assemblies includes a pin driver, both said pin and pindriver having ridged and grooved abutted edge portions near the shearline to forestall picking of the tumbler assembly.